A differential pressure transducer is a device which provides an output which is the difference between two input pressures. For example, when a pressure P1 is applied to one face of a deflecting diaphragm and a pressure P2 is applied to the other face of the deflecting diaphragm the resulting deflection will be determined by the difference in pressure (as for example P1−P2). There are other differential pressure transducers which essentially use two separate semiconductor structures. Each structure has its own diaphragm and the piezoresistors employed on the diaphragm surfaces are connected together to form a bridge which will provide a differential output. Reference is made to U.S. Pat. No. 6,595,066 entitled Stopped Leadless Differential Sensor issued on Jul. 22, 2003 to A. D. Kurtz, et. al. and assigned to the assignee herein. That patent shows a differential transducer where the pressure is applied to the top face or the top side of the diaphragm and to the bottom face or bottom side of the diaphragm to obtain a differential output. The patent shows a Wheatstone Bridge array consisting of piezoresistors which vary resistance according to the magnitude of a pressure or force applied to the diaphragm.
However, in prior art devices which utilize a force applied to two separate diaphragms, there is a problem in low pressure devices to bring out the leads. This problem resulting in one of the diaphragms of the differential transducer being smaller than the other diaphragm. In any event, it is known that the diaphragm size affects the operation of such a device. The larger the diaphragm, the less the back pressure, and the larger the diaphragm, the more compliant the diaphragm is. Therefore a large diaphragm is more compliant and will experience less back pressure than a smaller diameter diaphragm. Because of problems associated with bringing out leads, which will be further explained, different size diaphragms were traditionally used. One diaphragm was larger in diameter than the other thus resulting in pressure variations that compromised the operation of such devices. The lead problem required that the terminals from the pressure sensor be arranged in a circle about the periphery of the housing, resulting in different diameter diaphragms.